Easy starter for combustion engines



Oct. 19, 1965 P. JOHNSON EASY STARTER FOR COMBUSTION ENGINES Filed Feb. 5. 1964 a w. J m J/ F a H 6 m 4 1, 1 Q h 66 or A/ M, 1, &/ a

a fi m United States Patent 3,212,487 EASY STARTER FOR COMBUSTION ENGINES Philip L. Johnson, 9710 Ocean Gate Ave., Inglewood, Calif. Filed Feb. 3, 1964, Ser. No. 342,075 6 Claims. (Cl. 123-185) The present invention relates to a device which permits the easy starting of a combustion engine, particularly of a 2-cycle engine which is not provided with an automatic starter.

Two-cycle engines of the low horse-power types are usually provided with a starter cord, terminating in a handle which has to be pulled off a retaining drum so as to impart to the drive shaft of the engine a speed above the stall speed. Experience has shown that these engines start rather heavily, and persons who are somewhat weak physically are rarely able to start an engine without considerable and exhausting effort. The reason for this, of course, is that the cord is being pulled out against the compression forces in the engine, which forces must be overcome. Since a weaker person is rarely able to accomplish this, the engine speed during his efforts remains below the stall speed.

It is an object of the present invention to remedy the above-mentioned deficiency and to insure that, by one single pulling action, an operator is able to start such an engine safely.

It is another object of the present invention to provide an accessory device which can be attached, preferably releasably attached, to an existing starting cord with handle and which accessory device enables the user to start an engine safely without requiring him personally to impart a speed to the engine above stall speed.

It is a feature of the present invention to provide an accessory, the salient feature of which is a resilient element, such as a spring [or several springs, which are attached, or are to be attached, with one end or ends to the already existing handle of the starter cord. Attachment is made by means of a releasable clamping device. The spring or springs have their respective other ends secured to an auxiliary handle. If the starter cord is now being pulled out by means of the auxiliary handle, it has been found that, during this pulling operation, the spring or springs are being loaded. This pulling lasts for a relatively long time as compared with the duration of one cycle at a speed above stall speed. The spring or springs are expanded because the inertia of the engine acts against the pull. The spring or springs will be expanded primarily during the first attempt by the operator to move the engine through the first compression cycle. At the next or one of the next following exhaust cycles, the restarting force of the engine is reduced, and the reaction force of the spring or springs is so large that the spring or springs will rapidly discharge their stored energy. During this discharge, the auxiliary handle is still moved rather slowly by the operator while the cord with its handle rapidly moves towards the auxiliary handle, thus continuing the pulling of the cord but at a considerably higher rate than before. The discharge of the resilient energy, of course, results in a damped oscillation of the two handles against each other. This oscillatory motion serves to impart a high force and, therefore, high-speed motion to the manual handle and the starter cord, so that the speed imparted, in turn, to the drive shaft of the engine is well above the stall speed.

It is thus a feature of the present invention to provide an auxiliary device attachable to the manual starter device of a combustion engine and capable of storing energy during the first portion of the manual starting operation, which is conducted at a relatively low speed and for a relatively long period of time. During one 3,212,487 Patented Oct. 19, 1965 ice exhaust cycle, energy previously stored is discharged rapidly, resulting in a high-speed pulling action for the manual starter device.

While the specification concludes with claims particu larly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the in vention, and further objects, features, and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 illustrates a side view of the preferred embodiment of the invention in cooperation with a low horsepower, 2-cycle combustion engine;

FIGS. 2 and 3, respectively, show a front and a side elevation of a clamping element, with which the auxiliary accessory shown in FIG. 1 can releasably be attached to the already existing handle of the manual starter device of the engine as also shown in FIG. 1;

FIG. 4 illustrates the clamping device as it is attached to the starter handle of the engine; and I FIGS. 5 and 6, respectively, illustrate a side and a front elevational view of a modified auxiliary starter for an engine of the same type illustrated in FIG. 1.

Preceeding now to the detailed description of the draw: ings, FIG. 1 thereof shows the preferred embodiment of the invention in cooperation with a low horse-power, 2-' cycle combustion engine 10. There is provided a reeling drum 11 for a starter cord 12 covered by a housing 11a. Drum 11 then is geared to the drive shaft 10a in the engine through a one-way clutch. This is conventional. Normally, upon pulling out cord 12, the engine should be started.

Cord 12 terminates externally in a handle 13. This handle 13 has two arms, which normally serve for manual gripping. Handle 13 is substantially cylindrical, and a tubular extension 1311 is attached laterally to this handle, with the axis of tubular extension 13a extending trans versely to the axis of cylindrical handle 13. Tubular extension 13a is welded or otherwise secured to the handle proper and receives the end of cord 12, which is thus anchored in the interior of tube 13a. In order to secure the inventive attachment to handle 13, there is first provided a clamping member which is comprised of a U-shaped sheet 14 having retainer keyholes 15 and 16 at or near the ends of legs 14a and 14b, respectively, of the U. Adjacent the yoke of this U-shaped sheet 14, there are provided shouldered rivets 17 and 18, each having a retaining head. The rivets are provided in symmetrical relationship to the legs 14a and 14b.

For attaching this clamping member to the handle 13, the two legs 14a and 14b of the sheet 14 are being bent back (see FIG. 3) so that the two keyhole-type slots 15 and 16, respectively, receive rivets 17 and 18, whereby the relatively wide head of each rivet passes into the larger portion of the retainer holes, and the shoulder of each rivet then shifts into the short, smaller, and elongated portion of each retainer keyhole 15 and 16, as is shown best in FIG. 4. The two legs of U-shaped sheet 14 are being bent around the handle 13 prior to the insertion of rivets 17 and 18 into holes 15 and 16, respectively.

This clamping member 14 has, additionally, two holes 19 and 20 for respectively receiving the hooked ends of two springs 21 and 22. These two springs are conventional coil springs made of steel, which, with their respective other ends, are respectively hooked into corresponding holes pertaining to an auxiliary handle 23.

One can see that the auxiliary devicewhich includes clamping member 14, springs 21 and 22, and handle 23- can be removed from handle 13. Of course, the principal method of removal comprises unfastening the legs 14a and 14b from the rivets 17 and 18, respectively, and bending the legs 14a and 14b back. As long as legs 14a and 14b of the U-shaped sheet 14 retain some resiliency, the clamping device can be unlocked very easily from handle 13 by merely shifting the legs, so that the large portion of keyhole slots 15 and 16 registers with the heads of the shouldered rivets 17 and 18, and the latter can be removed through keyhole slots 15 and 16. Thus, the entire clamping mechanism is released in a very simple manner.

Another way to remove the auxiliary device may include a partial removal by hooking the springs out of the retainer holes 19 and 20. In this case, clamping member 14 remains locked to handle 13.

It should be mentioned that the specific configuration of the clamping means employed in the preferred embodiment of the invention does not by itself constitute a salient element. It is only important that the ends of springs 21 and 22 are linked to the end of cord 12 in such a manner that the direction of the combined resilient action and reaction of the two springs coincides with the direction of the cord 12 when the cord 12 is being pulled off drum 11. This symmetrical relationship is illustrated best in FIG. 1.

For starting engine 10, the operator grips handle 23 and pulls thereby cord 12 out of cover 11a. Thus, clamping member 14 locks its rivets positively into the keyholes. The operators aim is to impart to the engine a speed above the stall speed, so that the engine can turn over at least once. However, the manually imparted speed very often does not sufi'ice to start the engine without the inventive accessory. Presently, when cord 12 is pulled by means of handle 23, springs 21 and 22 will be loaded, but the shaft rotation is too slow for starting during spring loading. After the first or one of the following compression cycles, springs 21 and 22 will recoil and thereby impart to handle 13 and cord 12 a sudden, oscillatory motion which now suffices to rotate the engine above stall speed through several cycles, so that the engine will be started after the manual starting operation.

Ordinarily, a person wishing to start a 2-cycle engine will try, more or less rapidly, to pull the cord out of cover 11a through handle 13, and he will try to impart directly to drum 11 and shaft a a speed above stall speed during the entire pulling operation. Thus, within his ability, he exerts upon the engine a particular force over a rather long period of timelong as compared with the time it takes an engine to turn over at least once and to run through a few compression cycles. Roughly speaking, it takes normally about one second to unwind cord 12 from drum 11, while one or two cycles in a Z-cycle engine require a time which is in the order of magnitude of 100 milliseconds.

The invention now serves as a force-time integrator in that the power effort by the operator wishing to start the engine is first partially dissipated, and he first and primarily loads springs 21 and 22 when he pulls out the cord. The springs are expanded primarily when the operator moves the engine through the first compression cycle. Thus, at first he merely accelerates the drive shaft out of the resting position and up to a speed which may be well below the stall speed. During this pulling-out operation, which lasts for half a second or longer, the springs are being loaded, i.e., expanded; the engine, when being moved through a compression cycle, offers a relatively high resistance whereby an increased amount of force is imparted to the springs. This spring loading may require a period of time that is equal to the time it takes to pull most of the cord off drum 11.

In other words, during this pull-out operation of about one second, the springs are being expanded from their initial length 1 to a length 1', which is larger than 1. Expansion occurs primarily during an attempt of the operator to pull the engine through the first compression cycle. The resilient energy then stored in the springs is proportional to (l'l) During the expansion of the springs,

cord 12 is by no means unwound completely, so that, when the springs recoil, the energy stored previously in springs 21 and 22 is released rather rapidly.

It should be observed that, after the engine has been moved manually through the first compression cycle, the springs may not be loaded sufficiently, and during the next exhaust cycle the springs may slightly but not completely recoil. However, after passing through a few compression cycles, the springs will be expanded to such an extent that they will recoil rapidly during the following exhaust cycle. The recoiling of springs 21 and 22 is transmitted as rapid motion only upon handle 13 and cord 12. This motion sufiices to pull the engine through at least one compression cycle at the required rate for starting the engine.

A fairly high momentum is imparted momentarily to cord 12 and the drive shaft during the recoiling of the springs, and this high momentum results in a very high speed of the shaft, sufficient to run the engine through several compression cycles well above stall speed so that the engine will start safely. It has been found that this release of stored resilient or spring energy requires a period of time shorter by almost one order of magnitude in comparison with the loading time.

The arrangement as described thus far inherently includes an important safety feature. In case the engine should backfire, the resulting motion of handle 13 will be substantially taken up by springs 21 and 22 so that no shock movement is transmitted upon auxiliary handle 23. The resiliency of the springs dampens any such shock.

In order to practice the invention, it is necessary for the two springs 21 and 22 to be strong enough so that during operation they will not be stretched completely. On the other hand, these two springs must not be too strong, for they must be capable of being stretched to some extent by the operator. These requirements, however, afiord a large range of usable springs. In addition, the springs have to be selected to match the engine to be started; for example, a stronger engine, which is more diflicult to start, requires somewhat stronger springs.

FIGS. 5 and 6 illustrate a modified embodiment in that only one spring 25 is being used. This spring 25 is made of a heavy, flat, clock spring wire having a terminal arm 26 which is riveted to two clamping rings 27 and 28.

The clamping ring 27 is secured to arm 26 by means of a rivet 31, and a releasable screw 32 locks the clamping ring 27 around handle 13. The clamping ring 28 is secured to spring arm 26 by means of a rivet 33, and a releasable screw 34 locks the ring to handle 13. Clamping rings 27 and 28 are thus releasably connected to handle 13. The upper portion of spring 25 terminates in a loop 29. The upper transverse portion of this loop receives a roller 30 as the auxiliary handle. This handle 30 has a longitudinally extending slot to receive this upper transverse portion of loop 29. Since the operator will grip handle 30, a loop such as loop 29 is required to order to avoid damaging his fingers with the rebounding spring 35 upon starting.

It is a significant feature of the present invention, which has been developed above, that in one continuous starting operation the drive shaft of the engine is being rota-ted out of its resting position while concurrently thereto the springs are being loaded. 'Ilhe springs unload automatically when the engine offers insufiic ient resistance for funther expansion of the springs, whereupon the remaining portion of the starter cord is pulled from mhe drum, primarily by recoiling of the springs and at such a high speed that the engine will start positively. The interaction of slow spring loading and rapid unloading, with an automatic changeover from loading "to unloading, is due only to the fact that a manually exerted and relatively small amount of power is being tnansmitted upon the drive shaft through a resilient element or elements, which transmission lasts for a relatively long period of time. The pes ilient element "or elements store some of the energy thereby transmitted during the first part of the starting operation. After the springs have sufficiently expanded during one or a few compression cycles, the resilient element automatically unloads its stored energy during next exhaust cycle and in a very short period of time, thus exerting upon the drive shaft a high-powered iorce of a magnitude suflicient to accelerate the drive shaft to a speed well above stall speed and lasting through several cycles.

The invention is not limited to the embodiments described above, but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be covered by the following lOlfliITlS.

What is claimed is 1. An accessory for starting a combustion engine, there being a starter cord with a handle, which cord is operatively coupled to the drive shaft of the engine tor manually starting the engine, comprising:

an auxiliary handle;

clamping means for releasable attachment to the handle of the starter cord and having retaining means; and

spring means interposed between said auxiliary handle and said clam-ping means and engaging said retaining means, ior oscillating said starter cord handle against said auxiliary handle after said starter cord handle has been pulled for starting, via said auxiliary handle, said spring, and said clamping means, and said spring means has been loaded, thereby to move the drive shaft of the engine through at least one compression cycle.

2. An accessory ior starting a combustion engine, there being a starter cord with a handle, which cord is retained on a drum coupled to the drive shatt of the engine, ior manually star-ting the engine, comprising:

an auxiliary handle having two ends;

a clamping means for attachment to the handle of said starter cord .and having retaining means; and

two springs respectively interconnecting the two ends of said auxiliary handle with said retaining means of said clamping means, in symmetric relationship to said cord, said spring means being adapted for oscillating said starter cord handle against said auxiliary handle after a portion of said starter cord has been pulled manually oil? the drum, via said auxiliary handle, said springs, and said clamping means, to move the drive shatt of the engine through at least one compression cycle.

3. An accessory ior starting a combustion engine, there being a starter cord with a handle, which cord is retained on a drum coupled to the drive shait of the engine, rfior manual-1y starting the engine, comprising:

an auxiliary handle;

a clamping means tor releasable attachment to the handle of said starter cord in substantially sym metrical relation to said cord; and

a flat spring interposed between said auxiliary handle and said clamping means for oscillating said starter cord handle against said auxiliary handle after a portion of said starter cord been pulled manually oil the drum, via said auxiliary handle, said sprint and said clamping means, to move the drive shat-t of the engine through at least one compression cycle.

4. An accessory cfior starting a combustion engine, there being a starter cord with a handle, which cord is operatively coupled to the drive shaft of the engine for manually starting the engine, comprising:

an auxiliary handle;

clamping means fior releasable attachment to the handle of the starter cord, and having (retaining means; and

spring means interposed between said auxiliary handle and said clamping means and engaging said retaining means, said spring means being slowly loaded when said cord is being pulled by said auxiliary handle, said spring means being dimensioned to unload rapidly after a compression cycle betore pulling of said cord has been completed, thereby rapidly pulling a further portion of said cord and at a speed substantially higher than the cord speed during loading of the spring means. '5. An accessory for starting a combustion engine, there being a starter cord with a handle, which cord is operatively coupled to the drive shaft of the engine for manually starting the engine, the cord being resiliently retained on a drum, comprising:

an auxiliary handle; clamping means for releasable attachment to the handle of the starter cord in substantially symmetrical relation to the cord and having retaining means; and

spring means symmetrically engaging said clamping means at said retaining means so that the spring iorce is aligned with said starter cord, said spring means further engaging said auxiliary handle, so that upon manually pulling said handle, said spring means is being loaded slowly while most of the cord is being reeled from the drum, said spring means rapidly discharging its stored resilient energy after passage of the engine through a compression cycle, whereby another portion of the cord is reeled iirom said drum and at a high speed.

6. An accessory for starting a combustion engine, there being a starter cord with a handle, which cord is operative'ly coupled to the drive shait of the engine for manually starting the engine, the cord being resiliently retained on a drum, comprising:

an auxiliary handle;

clamping means lfor releasable attachment to the handle of the starter cord in substantially symmetrical relation to the cord and having retaining means; and

a pair of coil springs symmetrically engaging with one end each said clamping means at said retaining means so that the total spring iorce is aligned with said starter cord, said pair of springs with their respective other ends further engaging said auxiliary handle, so that, upon manually pulling said handle, said pair of coil springs is being loaded slowly While mos-t of the cord is being reeled 'from said drum, said pair of springs rapidly discharging the stored resilient energy after passage of the engine through a compression cycle, whereby another portion of the cord is reeled irom said drum and at a high speed.

References Cited by the Examiner UNITED STATES PATENTS 2,286,419 6/ 42 Krenzke 123-485 2,448,844 9/ 48 Throsel 123 l'85 FOREIGN PATENTS 3,645 2/ 13 Great Britain.

MARK NEWMAN, Primary Examiner.

RIC-HARD B. WILKINSON, Examiner 

1. AN ACCESSORY FOR STARTING A COMBUSTION ENGINE, THERE BEING A STARTER CORD WITH A HANDLE, WHICH CORD IS OPERATIVELY COUPLED TO THE DIRVE SHAFT OF THE ENGINE FOR MANUALLY STARTING THE ENGINE, COMPRISING: AN AUXILIARY HANDLE; CLAMPING MEANS FOR RELEASABLE ATTACHMENT TO THE HANDLE OF THE STARTER CORD AND HAVING RETAINING MEANS; AND SPRING MEANS INTERPOSED BETWEEN SAID AUXILIARY HANDLE AND SAID CLAMPING MEANS AND ENGAGING SAID RETAINING MEANS, FOR OSCILLATING SAID SRARTER CORD HANDLE AGAINST SAID AUXILIARY HANDLE AFTER SAID STARTER CORD HANDLE HAS BEEN PULLED FOR STARTING, VIA SAID AUXILIARY HANDLE, SAID SPRING, AND SAID CLAMPING MEANS, AND SAID SPRING MEANS HAS BEEN LOADED, THEREBY TO MOVE THE DRIVE SHAFT OF THE ENGINE THROUGH AT LEAST ONE COMPRESSION CYCLE. 